Achievement of Low-Energy Buildings in High-Latitude Countries Through Passive Solar Systems

Abstract

The architecture and civil engineering design of buildings are crucial for their energy needs. To create low-energy buildings, it is necessary to take into account geographical and climatic conditions, including availability of solar energy. The architecture, shape, structure and materials of a building can all help to use solar energy both when its availability is small and to protect a building against overheating when there is excess solar energy. Well-thought-out design and construction of a new building are the most simple ways of reducing building energy needs. Utilization of solar energy should be done in a passive and planned way. Not all standard passive solar systems are effective solutions in high-latitude countries. Passive systems in the form of solar buffer spaces can be recommended. Regular solar buffer spaces in the form of greenhouses can be attached to buildings at the south side in moderate climates. However, in high-latitude countries, the climatic conditions can be more severe in winter (too low ambient air temperature and solar irradiance) and in summer (too high ambient air temperature and solar irradiance) so that a specific type of buffer spaces is necessary. In the case of severe winter and high latitude, the buffer spaces should be incorporated into the interior of the building (not attached to it). They should contain two cuboid subspaces with a transparent partition between them, or with no partition but with a specific internal overhang designed carefully to protect the interior of the building against too much solar irradiation in summer and not to block the sun in winter. Any building of cuboid shape should have a main façade exposed to the south; the extension in direction east--west to direction south--north should be in the range from 1.5:1 to 2:1. In the case of glazed semi-cylindrical façades, the extension of the glazed façade should be limited by the range of azimuth angles of the sunrise and sunset in winter (in December) in a given geographical location. The paper underlines the role of solar energy in the energy balance of a building, in reducing the energy needs of a building in a passive way. When energy needs are really reduced significantly then innovative energy systems can be introduced. Modern solar passive technologies help us to realize ideas that have already been discovered in the past, by traditional architecture and civil engineering methods.